oracle 最简单的学习笔记，增删改查，PLSQL基本语法，游标，函数，存储过程的实现

-----创建序列
create sequence book_id
INCREMENT BY 1 -- 每次加几个 　
　START WITH 001 -- 从1开始计数 　
　NOMAXVALUE -- 不设置最大值 　
　NOCYCLE -- 一直累加，不循环 　
　CACHE 10;



------创建books表
create table books(
books_id varchar2(1000),
books_name varchar2(100),
price number,
qty number,
pub varchar2(200)
);


------修改books表的字段
alter table books modify(books_id number)

-------------往books表中插入数据
insert into books values(book_id.nextval,'中国文学1',39,12,'人民文学');
insert into books values(book_id.nextval,'中国文学2',30,32,'人民文学');
insert into books values(book_id.nextval,'中国文学3',59,22,'清华大学');
insert into books values(book_id.nextval,'中国文学4',33,52,'清华大学');
insert into books values(book_id.nextval,'中国文学5',99,62,'电子工业');

-----------跟新books中的信息
update books set price=100 where books_id=1




----------按出版社分组查询每个出版社金额的情况
select pub,sum(price*qty) from books group by pub


----------按出版社、书籍名称分组查询每个出版社金额的情况
select pub,books_name,sum(price*qty) from books group by pub,books_name

----------按出版社、书籍名称分组查询每个出版社金额的情况   >50
select pub,books_name,sum(price*qty) from books group by pub,books_name having sum(price)>50

----------查询相同出版社的记录数
select pub,count(pub) from books group by pub having count(pub) >1


-----标的内链接
select eid ,ename,six,name from e,d where a.id=d.id

select eid ,ename,six,name from e join d on a.id=d.id

-----做外连接
select eid ,ename,six,name from e join d on a.id=d.id(+)
----右外连接
select eid ,ename,six,name from e join d on a.id(+)=d.id

----无关子查询
select * from e where id in (select eid from d)

----相关子查询
select * from e where id in (select eid from d where id=d.id and id='003')

select * from e where id not in (select eid from d where id=d.id and id='003')


-----存在则显示
select * from e where exists(select id from d where id=d.id)

-----不存在则显示
select * from e where not exists(select id from d where id=d.id)




-----------------------PLSQL基本语法----------------------------------------------------------------------------------------------------------
set serveroutput on size 10000
declare
x varchar2(100);
begin
x:='This is ....';
DBMS_OUTPUT.PUT_LINE('x value is '||x);
end;
 
-----if  elsif   else
declare
  a number;
  b varchar2(10);
begin
  a := 2;
  if a = 1 then
    b := 'A';
  elsif a = 2 then
    b := 'B';
  else
    b := 'C';
  end if;
  DBMS_OUTPUT.put_line(b);
end;


----------------case
declare
  a number;
  b varchar2(10);
begin
  a := 2;
  case
    when a = 1 then
      b := 'A';
    when a = 2 then
      b := 'B';
  end case;
  DBMS_OUTPUT.put_line(b);
end;


-------------------------PLSQL  循环--------------------------------------------

------loop
declare
  x number;
begin
  x := 1;
  loop
    x := x + 1;
    if x > 3 then
      exit;
    end if;
    DBMS_OUTPUT.put_line(x);
  end loop;
  DBMS_OUTPUT.put_line(x);
end;

--------------while
declare
  x number;
begin
  x := 1;
  while x > 3 loop
    x := +1;
    DBMS_OUTPUT.put_line(x);
  end loop;
  DBMS_OUTPUT.put_line(x);
end;

-------for

begin
  for x in 1 .. 10 loop------从小到大
    DBMS_OUTPUT.put_line(x);
  end loop;
  DBMS_OUTPUT.put_line('end of for loop');
end;

begin
  for x in  reverse 1 .. 10 loop------从大到小
    DBMS_OUTPUT.put_line(x);
  end loop;
  DBMS_OUTPUT.put_line('end of for loop');
end;



----------------做标签
declare
  x number;
begin
  x := 0;
  <<repeat_loop>>
  x := x + 1;
  DBMS_OUTPUT.put_line(x);
  if x < 3 then
    goto repeat_loop;
  end if;
end;




----------------exception 处理-------------------------------------
declare
  test varchar2(100);
begin
  select books_name into test from books where books_id = 1;
  DBMS_OUTPUT.put_line(test);
  exception
  when no_data_found then
    DBMS_OUTPUT.put_line('没有找到数据');    
end;


-----------自定义异常
declare
  test varchar2(100);
  e exception;
begin
  select books_name into test from books where books_id = 1;
  if test <> '中国文学1' then
    raise e;
  end if;
  DBMS_OUTPUT.put_line(test);
exception
  when e then
    DBMS_OUTPUT.put_line('不是需要的书籍名称');
end;


-----------------------记录的声明-------------------------------
declare
type myrecord is record(
bname varchar2(100),
bpub varchar2(100)
);
real_record myrecord;
begin
select books_name,pub into real_record from books where books_id=1;
DBMS_OUTPUT.put_line(real_record.bname || real_record.bpub);
end;

declare
  type myrecord is record(
    bname books.books_id%type, ---------------声明的字段和表中的字段类型一样
    bpub  varchar2(100));
  real_record myrecord;
begin
  select books_name, pub into real_record from books where books_id = 1;
  DBMS_OUTPUT.put_line(real_record.bname || real_record.bpub);
end;


declare
  myrecord books%rowtype;
begin
  select * into myrecord from books where books_id = 1;
  DBMS_OUTPUT.put_line(myrecord.books_name || myrecord.pub);
end;




-----------------------游标--------------------

----显示游标的使用方法
declare
  cursor mycursor is
    select * from books;
  myrecord books%rowtype;
begin
  open mycursor;
  fetch mycursor
    into myrecord;
  while mycursor%found loop
    DBMS_OUTPUT.put_line(myrecord.books_name || myrecord.pub);
    fetch mycursor
      into myrecord;
  end loop;
  close mycursor;
end;


------带参数的游标
declare
  cursor mycursor(bookid number) is
    select * from books where books.books_id = bookid;
  myrecord books%rowtype;
begin
  open mycursor(1);
  fetch mycursor
    into myrecord;
  while mycursor%found loop
    DBMS_OUTPUT.put_line(myrecord.books_name || myrecord.pub);
    fetch mycursor
      into myrecord;
  end loop;
  close mycursor;
end;

------使用for做游标的循环
declare
cursor mycursor(bookid number) is
select books_name from books where books.books_id=bookid;
begin
for cur in mycursor(1) loop
DBMS_OUTPUT.put_line(cur.books_name);
end loop;
end;





----is open
declare
  bookname books.books_name%type;
  cursor mycursor(booksid number) is
    select books_name from books where books_id = booksid;
begin
  if mycursor%isopen then
    DBMS_OUTPUT.put_line('cursor is opened');
  else
    open mycursor(1);
  end if;
  fetch mycursor
    into bookname;
  close mycursor;
  dbms_output.put_line(bookname);
end;

-------rowcount
declare
  bookname books.books_name%type;
  cursor mycursor is
    select books_name from books;
begin
  open mycursor;
  loop
    fetch mycursor
      into bookname;
    exit when mycursor%notfound or mycursor%notfound is null;
    DBMS_OUTPUT.put_line(mycursor%rowcount);
  end loop;
  close mycursor;
end;
   
-----游标跟新数据
declare
  cursor mycursor is
    select books_name from books for update;
  text varchar2(100);
begin
  open mycursor;
  fetch mycursor
    into text;
  while mycursor%found loop
    update books
       set books_name = books_name || '_t'
     where current of mycursor;
    fetch mycursor
      into text;
  end loop;
  close mycursor;
end;

----------------隐式游标   不需要声明
begin
  for cur in (select books_name from books) loop
    DBMS_OUTPUT.put_line(cur.books_name);
  end loop;
end;



--------------------存储过程------------------------------------------------------------------
create or replace procedure getBookNameById(bookid in number) is
  bookname varchar2(100);
begin
  select books_name into bookname from books where books_id = bookid;
  --select books_name               from books where books_id=1;
  dbms_output.put_line(ookbname);
end;
end getBookNameById;

-----
begin调用过程
test.getBookNameById(1);
end;
----调用过程
execute test.getBookNameById(1);

-----显示某个存储过程的错误信息
show errors procedure getBookNameById;







SELECT * FROM
(
SELECT A*, ROWNUM RN
FROM (SELECT * FROM books) A
)
WHERE RN BETWEEN 1 AND 5



select count(*） from (select * from books);